Comparative analyses of phenotypic characteristics of TROL KO mutant and wild-type Arabidopsis thaliana (L.) Heynh.

Biljni organizmi fotosintetskim reakcijama pridonose proizvodnji organske tvari u ekosustavu i nastajanju kisika, prijeko potrebnih komponenti energetskog metabolizma velike većine bioloških organizama. Bitna točka fotosinteze nalazi se na razmeđi reakcija ovisnih o svjetlu i Calvinovog ciklusa: redukcija NADP+ posredstvom feredoksin:NADP+ reduktaze (FNR). U prošlom je desetljeću otkriveno da je za uspješno funkcioniranje enzima FNR prijeko potrebna njezina interakcija s transmembranskim proteinom TROL (thylakoid rhodanase like protein). U ovom je radu istražen učinak odsustva proteina TROL (knock-out mutacije TROL) na krajnje fenotipske značajke učinkovitosti fotosinteze – suhu biomasu, površinu listova i koncentraciju fotosintetskih pigmenata. Uz kontrolnu grupu biljaka uzgajanu u optimalnim uvjetima, dio biljaka je uzgajan u uvjetima manjka vode radi dodatnog potvrđivanja utjecaja proteina TROL na usmjeravanje elektrona s FNR u biosintezu šećera. Zaključno, knock-out mutacija TROL (TROL KO) u slučaju biljaka uzgajanih na zemlji s normalnom količinom vode dovodi do 40%- tnog smanjenja biomase i 20%-tnog smanjenja površine listova u odnosu na divlji tip, dok u uvjetima manjka vode mutirane biljke pokazuju veću otpornost. Mjerenja koncentracije fotosintetskih pigmenata nisu pokazala značajne promjene između mutanata i divljeg tipa uročnjaka. Međutim, koncentracije klorofila a i b u uročnjacima divljeg tipa izloženih sušnom stresu značajno su porasle, što zahtjeva dodatna istraživanja.Plant organisms with their photosynthetic activity largely contribute to the environment in outputting organic compounds and oxygen involved in the most fundamental biological processes. The essential point of photosynthesis is situated at the intersection of light-dependent reactions and the Calvin cycle, specifically, the reduction of NADP+ via ferredoxin:NADP+ reductase (FNR). Over the past decade, it has been discovered that the interaction of the transmembrane protein TROL (thylakoid rhodanase like protein) is essential for the efficient functioning of FNR. This work investigated the effect of TROL knock-out mutation on the final phenotypic characteristics of efficient photosynthesis, like dry biomass, leaf area, and the concentration of photosynthetic pigments. Alongside the control group of plants grown in optimal conditions, a portion of plants was grown in drought conditions, to further prove the effect of TROL protein on channelling the electrons from FNR to sugar biosynthesis. Finally, the TROL knock-out mutants (TROL KO) exhibit 40% loss in dry weight and 20% reduction of leaf area in plants cultivated on regularly watered soil, whereas the same plants in drought conditions exhibit increased resilience. Measurements of the photosynthetic pigment concentrations did not show significant changes between mutants and wild-type. However, the concentrations of chlorophyll a and b in wild-type Arabidopsis exposed to drought stress increased significantly, which requires further research